A jointer is designed to allow an operator to form a precise angle between two surfaces on a work piece, usually a wood board to be used in a final product such as furniture, cabinetry, interior trim, and the like. Often, the angle between the two surfaces must be exact to obtain a final product of high quality.
The jointer comprises a table assembly having first and second table sections. A gap is formed between the two table sections. A cutter assembly defining a cylindrical cutting path is mounted to the table assembly between the first and second table sections such that the cutting path extends into and along the length of the gap. A jointer fence assembly is mounted to the table assembly such that a jointer fence surface is supported above the first and second table sections and extends across the gap; the jointer fence defines, and thus will be parallel to, the direction of travel of the work piece during cutting. In particular, the operator places the work piece on the first table section and, while firmly holding the work piece against the jointer fence surface, slides the work piece over the gap. The cutter assembly removes a small amount of the work piece as the work piece slides over the gap.
The gap defines a gap width, a gap length, and a gap offset. The gap width is the distance between the first and second table sections in the direction of travel of work piece. The gap length is the dimension of the gap in a direction transverse to the direction of travel of the work piece. The first and second table sections define first and second planar table surfaces, respecively. Normally, the second table surface will be approximately the same height as the cutting plane and slightly higher than the first table surface so that the work piece is stably supported after it has been cut. The gap offset is the difference in vertical height between the first and second table surfaces.
Often, the jointer fence assembly is adjustable such that a location of the jointer fence assembly along the gap length can be adjusted. This allows the amount of exposed gap (and thus rotating cutter assembly) to be controlled to just the amount necessary for the dimensions of the work piece being cut.
The surface of the work piece that is held against the jointer fence surface will be referred to herein as the reference surface. The surface that is cut by the jointer cutter assembly will be referred to as the cut surface. The angle between the jointer fence surface and the longitudinal axis of the cylindrical cutting path will be referred to herein as the jointer fence angle. The angle between the reference and cut surfaces after the cut has been made will be referred to as the cut angle. The jointer fence angle will define the cut angle.
Normally, while designing the final product, the operator determines a desired angle between the reference surface and the cut surface. To ensure that the actual cut angle formed equals the desired angle, the jointer fence angle must be set precisely and the fence assembly locked in place such that this angle does not change during a given cut or even during subsequent cuts.
A number of factors complicate the design and fabrication of a jointer fence assembly that allows a jointer fence angle to be set accurately and consistently to match the desired angle. For example, the desired angle may be different for different cuts; the operator therefore must be able to adjust the jointer fence angle. To be adjustable, the fence assembly must use pivots or hinges that allow do not the fence assembly to move slightly when the work piece is securely held against the fence surface. Any such movement of the fence assembly may allow the jointer fence angle to deviate from the desired angle.
In addition, a design that allows the jointer fence surface to be moved across the length of the gap also creates the possibility of movement that allows the jointer fence angle to deviate from the desired angle.
The need thus exists for jointer fence systems and methods that may be manufactured at reasonable cost but which allow the formation of a cut angle that matches a desired angle with a high degree of accuracy.